Major etiologic investigations focus on working populations exposed to benzene, trichloroethylene, other organic solvents, formaldehyde, diesel exhausts, combustion products, electromagnetic fields, pesticides, and silica. Findings linking cancer with occupational exposures included an excess of nasopharyngeal cancer and leukemia among workers exposed to formaldehyde. Results from two studies suggest an association with myeloid leukemia. The first, an industrial cohort study of workers in formaldehyde industries indicate an association with myeloid leukemia, with risks that were persistently elevated over 40 years of follow-up time. In the second study, a case-control study of workers in the funeral industry, an elevated OR was found for those whose estimated cumulative formaldehyde exposure exceeded 9253 parts per million hours (OR = 3.1; 95% CI = 1.0 to 9.6, P = .047). Nasopharyngeal cancer was also associated with formaldehyde as measured by average intensity, peak exposure, cumulative and duration of exposure (p-trend = 0.066, 0.025, 0.001, and 0.147, respectively). Breast cancer among women in Shanghai was associated with employment in the textile industry, medical profession, and the telecommunications industry. A cohort of U.S. Coast Guard shipyard workers was found to have elevated mortality from emphysema, lung cancer, and mesothelioma, while a cohort of Coast Guard marine inspectors, who carry out ship inspections involving exposure to a variety of chemicals, showed excess deaths from cirrhosis of the liver and chronic rheumatic heart disease. Among other industrial studies, a cohort of workers engaged in the repair and maintenance of aircraft and missiles showed no clear exposure-response gradient for TCE with any cancer, but did show an approximately two-fold excess of renal disease. In a case-control study in Europe evaluated the risk of renal cancer, increased risk was observed among subjects ever TCE-exposed (OR=1.63;(1.04-2.54) compared to those never exposed. Exposure-response trends were observed among subjects above and below the median exposure [average intensity (OR=1.38;(0.81-2.35); OR=2.34;(1.05-5.21), p-trend=0.02). We have also reported findings from a variety of case-control studies that have examined occupation and cancer risks, including bladder cancer in Spain, kidney cancer in Europe, lung cancer in Russia and Turkey, pancreas cancer in Iowa, and breast cancer in Poland. Other studies are evaluating brain cancer risk from electromagnetic fields (EMF), relying on quantitative exposure estimates from job-specific modules. Methodologic studies dealt with confounding and exposure misclassification, quantitative exposure assessment, and exposures and urinary mutagenicity in rubber workers.